Facebook users spend most of their time in the News Feed, the river of information about your friends, and comparatively very little (just 10%) using apps according to a comScore report on how people use Facebook.

This is interesting because the biggest app company, Zynga, filed to go public, and more generally because tons of Facebook apps are getting zillions of VC money all the time.

If people spend so little time on Facebook apps, why the excitement?

First of all, 10% of usage on Facebook, the second biggest site in the world, is still a huge market.

It's definitely possible to build big businesses on the Facebook platform. But those numbers are a useful reality check: Facebook isn't becoming a new internet, with Facebook apps replacing websites, as some fear. People still overwhelmingly use Facebook for what it's designed for: knowing what our friends are up to.